Design and performance analysis of a sustainable high efficiency SnS-based heterojunction solar cell

Abstract This study presents the design, optimization, and performance evaluation of a high-efficiency SnS-based heterojunction solar cell. The optimized device architecture, FTO/CdZnS/SnS/Hole Transport Layer-(HTL)/Au, leverages Cadmium Zinc Sulfide (CdZnS) as the electron transport layer due to its high mobility, wide bandgap, and optical transparency, minimizing recombination losses. The comparison of two HTLs—Polytriarylamine (PTAA) and Nitrogen-Doped Titanium Dioxide (TiO 2 :N)— is presented here of which TiO 2 :N ensures efficient hole extraction and energy-level alignment with the SnS absorber, enhancing stability and performance. Optimization process analysed parameters such as acceptor and donor density, trap density, and absorber and transport layer thickness to maximize charge collection. Temperature-dependent studies confirmed the device’s robustness under varied conditions. Density Functional Theory simulations evaluated the electronic and optical properties of SnS, revealing strong absorption, favourable dielectric properties, and high reflectivity, reinforcing its photovoltaic-potential. The optimized device incorporating TiO 2 :N achieved a power conversion efficiency (PCE) of 37.85%, reflecting a 3.91% enhancement over previously reported designs. It also demonstrated an impressive fill factor (FF) of 86.16%, a short-circuit current density (Jsc) of 34.05 mA cm −2 , and an open-circuit voltage (Voc) of 1.29 V. This work demonstrates a promising approach to improving solar cell efficiency, stability, and scalability. Strategic material selection and advanced optimization techniques contribute to the sustainable development of next-generation photovoltaic technologies for renewable energy.